The effect of isolated tumor cells on adjuvant treatment decisions for patients with endometrial cancer: A retrospective case series.

Objective: Sentinel lymph node biopsy (SLNB) for endometrial cancer staging may identify isolated tumor cells (ITCs). Although guidelines do not classify nodes with ITCs as positive, earlier papers reported that a significant proportion of gynecologic oncologists treat ITCs as they would positive nodes. The objective of this study was to examine practice patterns and determine if the presence of ITCs in endometrial cancer affects adjuvant treatment decision-making. Methods: This was a retrospective series of patients with endometrial adenocarcinoma stages I to IIIB who underwent surgical staging with SNLB from July 2016 to January 2022 at three hospitals. The primary outcome of interest was the receipt of adjuvant treatment. Chi-square, Mann-Whitney Results: Of seven hundred thirty-four patients included, ITCs were identified in 41 patients (5.6 %). Deep myometrial invasion (61.0 % vs 20.5 %, p < 0.001) and lymphovascular invasion (58.4 % vs 17.7 %, p < 0.001) were more common in patients with ITCs than in those with negative lymph nodes. Patients with ITCs were more likely to receive adjuvant treatment (30 of 41, 73.2 % vs 289 of 693, 41.7 %, p < 0.001). When controlling for age, stage, histology, grade, and lymphovascular space invasion, ITCs were not associated with an increased likelihood of adjuvant therapy receipt. Conclusions: Although patients with ITCs were more likely to receive adjuvant treatment, this was accounted for by other clinical and histological factors. Clinicians were likely to make decisions based on established risk factors, and more data are needed on the role of ITCs in the landscape of molecularly based decision making.